Plain language summary
Inflammation is associated with the pathogenesis of insulin resistance, type 2 diabetes (T2D), and related complications. Lifestyle therapy is a frontline treatment for improving glucose control in people with T2D. The main aim of this study was to determine whether reducing hyperglycaemia with a low-carbohydrate high-fat (LC) diet could lower markers of innate immune cell activation and systemic inflammation in people with T2D. A secondary aim was to examine if the combination of an LCHF diet with strategically timed postmeal walking was superior to an LCHF diet alone. The study is a randomised cross over study which enrolled Individuals with physician-diagnosed T2D to complete three short-term controlled-intervention periods. Sixteen participants were enrolled (men = 8 and women = 8) who were aged between 48 and 72 years. Results indicate that while LC and LC together with exercise (LC+Ex) led to superior improvements in glucose control and fasting proinsulin (the pro-hormone precursor to insulin) levels as compared with low-fat low glycaemic index diet (GL), all three diets (GL, LC and LC+Ex), appeared to lower a particular marker of cellular inflammation over the short-term. Authors conclude that an LCHF diet with or without daily postmeal walks improved four-day glycaemic control and fasting proinsulin levels compared with a GL diet.
Abstract
Lowering carbohydrate consumption effectively lowers glucose, but impacts on inflammation are unclear. The objectives of this study were to: 1) determine whether reducing hyperglycemia by following a low-carbohydrate, high-fat (LC) diet could lower markers of innate immune cell activation in type 2 diabetes (T2D) and 2) examine if the combination of an LC diet with strategically timed postmeal walking was superior to an LC diet alone. Participants with T2D ( n = 11) completed a randomized crossover study involving three 4-day diet interventions: 1) low-fat low-glycemic index (GL), 2) and 3) LC with 15-min postmeal walks (LC+Ex). Four-day mean glucose was significantly lower in the LC+Ex group as compared with LC (-5%, P < 0.05), whereas both LC+Ex (-16%, P < 0.001) and LC (-12%, P < 0.001) conditions were lower than GL. A significant main effect of time was observed for peripheral blood mononuclear cells phosphorylated c-Jun N-terminal kinase ( P < 0.001), with decreases in all three conditions (GL: -32%, LC: -45%, and LC+Ex: -44%). A significant condition by time interaction was observed for monocyte microparticles ( P = 0.040) with a significant decrease in GL (-76%, P = 0.035) and a tendency for a reduction in LC (-70%, P = 0.064), whereas there was no significant change in LC+Ex (0.5%, P = 0.990). Both LC (-27%, P = 0.001) and LC+Ex (-35%, P = 0.005) also led to significant reductions in circulating proinsulin. An LC diet improved 4-day glycemic control and fasting proinsulin levels when compared with GL, with added glucose-lowering benefits when LC was combined with postmeal walking.
Methodological quality
Jadad score
:
3
Allocation concealment
:
Yes
